JP2001249640A - Driving method for plasma display panel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a driving method which reduces quiescent periods in the display of a PDP(plasma display panel) and increases luminance of the PDP and shortens unit display periods. SOLUTION: The field period of a picture signal is divided into N pieces (N is even number of 6 or more) of subfields and quiescent periods corresponding to the number of assigning intensity levels and the arranging of the subfields in the line of one side is performed so that odd numbered subfields are arranged in an ascending order by counting them in an order in which display periods become smaller and even numbered subfields are arranged in a descending order at the rear and the arranging of subfields in the line of other side is performed so that a subfield whose display period is the largest and odd number pieces of subfields are arranged in an order in which display periods become smaller at the same positions in the arrangement in the line of one side and subfields other than subfields of the same positions are arranged in an order reverse to the order in the line of one side.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of driving a plasma display panel (hereinafter, also simply referred to as a PDP), and more particularly, to a method of expressing a display gradation of each pixel by N bits, and a unit display period (PDP) for each pixel. For example, one field period or one frame period) is divided into the same number of subfield periods as the number of bits N corresponding to the number of display gradations, and the light emission time in each subfield period obtained by the division is divided into N bits. The present invention relates to a method of displaying a halftone image of an image signal by performing weighting in correspondence with each of the bits.

[0002]

2. Description of the Related Art When displaying a halftone of an image on a display screen using a device having a large threshold characteristic such as a PDP,
Generally, the light emission is performed by combining a plurality of light emissions having different light emission times according to the gradation of the image signal to be displayed.
Specifically, the image signal is converted into an N-bit image signal according to its luminance, and each field period is set to the N (N is 3).
The above-mentioned integer is divided into sub-field periods, and the sub-field period in which the light emission time is shortest is defined as the LS of the image signal.
B, the subfield period having the longest light emission time corresponds to the MSB of the image signal, and each subfield period corresponds to each bit of the image signal.

If the light emission time in the subfield period in which the light emission time is the shortest is ti, the light emission time in the other subfield periods is a power of 2 such as, for example, 2, 4, 8, or 16 times ti. The light emission time ta in the subfield period, which is set to be twice as long as the light emission time is the longest, is set to 2 (N-1) times of ti.
Then, the presence or absence of light emission in each subfield period is controlled according to the image signal.

FIG. 4 is a diagram showing electrode wiring of an AC type plasma display panel. As shown in FIG.
Three types of electrodes are wired on the panel 400, and X electrodes (electrodes for applying a sustain pulse for light emission display) 401 in the horizontal direction.
And the Y electrode (electrode for applying a scanning pulse) 402 are wired in parallel, and the A electrode (electrode for applying an address pulse) 403 is wired in the vertical direction. Then, a discharge cell 404 is formed at the intersection of the three electrodes. The plurality of X electrodes of the panel are all connected in common, or are connected in common by dividing them into odd lines and even lines. During the address period in each subfield period, an address pulse is applied to the A electrode and Y electrodes are applied. A scanning pulse is applied to the electrodes, and a sustaining pulse for light emission display is applied to the X electrode 401 and the Y electrode 402 during a display period.

FIG. 5 is a diagram showing a first conventional driving method of an AC type plasma display panel. Here, FIG.
Are connected and driven in common. FIG.
As shown in (a), for example, when the number of gray scales is 2 to the fifth power, that is, when halftones are displayed with 32 gray scales, one field display period (hereinafter, also simply referred to as a field period) 1F for each pixel (For example, (1/60) second (= about 16.7 ms
ec)) for five sub-field periods SF1, SF2,
.., Divided into SF5, and each subfield period S
F1, SF2,..., SF5 have at least an address period AP and a display period SP, and the display periods SP are weighted at a ratio of 1: 2: 4: 8: 16.

[0006] In the display period of each subfield period, a weighted number of sustain pulses are applied to the X electrodes of the PDP and the Y electrodes.
This is performed by applying the voltage to the electrodes, for example, by applying the number of binary code ratios. During the address period in each of the subfield periods, an address pulse is applied to the A electrode shown in FIG. 4, and the Y electrodes Y1, Y2, Y3,.
.., Yn are sequentially applied, and during the display period in each subfield period, a sustain pulse is applied to the X electrode, and pixels to emit light simultaneously emit light on the entire screen.

[0007] SF1 having the shortest light emission time corresponds to L of the image signal.
SF5 corresponding to SB and having the longest emission time corresponds to the MSB of the image signal, and other subfield periods also correspond to each bit of the image signal. The address period AP is the same in every subfield period. The display order of the subfield period corresponding to each bit is, for example, SF1, SF2, SF3, SF4, SF within the unit display period.
The order is fixed at 5. FIG. 5B shows a state of the scanning pulse 500 applied to the scanning electrodes (Y electrodes) of the PDP during the address period, and sequentially from the electrode Y1 of the first horizontal scanning line to the electrode Yn of the nth horizontal scanning line. Scan pulse 50
By applying 0, the address period in one subfield period ends. A indicates a predetermined address pulse 501 applied to the address electrode of the PDP, and the presence or absence of the address pulse is determined according to the gradation of the image signal.

FIG. 8 shows the correspondence between the subfield period lit by the address pal and the gradation of the image signal. In FIG. 8, a white frame indicates lighting, and a black frame indicates non-lighting. As shown in the figure, at gradation 1, only the subfield period SFO1 corresponding to the LSB is turned on, and at gradation 16, only the subfield period SFO5 corresponding to the MSB is turned on. Lighting and non-lighting in the subfield period are determined.

As described above, during the address period, the scanning pulse 500 corresponding to the image signal is applied in time series from the top of the Y electrode, and the Y electrode is scanned once from the upper line to the lower line. , The address period of one subfield period ends. A predetermined address pulse 501 is applied to the A electrode in synchronization with the scanning pulse 500. When the scan pulse and the address pulse overlap with each other in time, a discharge is generated, writing is performed by forming wall charges, and light is emitted by applying a sustain pulse during a display period.

In the above-described conventional halftone image display method,
Since the display order of the subfield periods SF1 to SF5 is constant (fixed), in a scene where a portion where brightness changes gradually, such as a human face, moves slowly, and a portion where brightness changes naturally gradually changes suddenly. However, there is a problem in that a significant change in brightness occurs and display quality is significantly impaired. FIG. 6 shows a conventional driving method of an AC type plasma display panel proposed as a method for solving the problem of the false contour failure.

FIG. 6 is a diagram showing a second conventional driving method of an AC type plasma display panel. The plasma display panel used in this driving method is the same as that shown in FIG. 4, but the driving method is different. That is, in the address period of each subfield period, a predetermined address pulse not depending on an image signal is applied to the A electrode (address electrode), and a scanning pulse according to the image signal is applied to the Y electrode. For the Y electrodes, the odd line group and the even line group are driven by different drive circuits,
In the scanning period in each subfield period, synchronization is performed so that the address period of the odd line group and the address period of the even line group have the same timing. In the display period SP in each subfield period, the X electrode and the Y electrode
A sustain pulse is applied to the electrodes, and the X electrodes are connected to the odd lines or the even lines in common, and the odd line group and the even line group are driven by different driving circuits. Then, SF1 of the odd line and SF2 of the even line
Are turned on at the same time, and similarly, SF3 of the odd line and SF4 of the even line are turned on at the same time. Thus, one subfield period of the odd line and one subfield period of the even line are simultaneously driven and turned on.

In the second conventional driving method of the AC type plasma display panel shown in FIG.
N) is set to 8 for one field period (1F)
For eight subfield periods (SF1, SF2, SF
3, SF4, SF5, SF6, SF7, SF8) and idle periods, and the arrangement (order of arrangement) of the periods of the subfields is reversed in the odd line group and the even line group. For example, as shown in FIG. 10A, odd-numbered lines are arranged with odd-numbered subfield periods in ascending order from the subfield period with a short display period SP, and after that, even-numbered subfield periods are arranged in descending order. . In the even-numbered lines, the sub-field periods are arranged in a completely reverse order to the odd-numbered lines, as shown in FIG. By arranging the sub-field periods in the above-described manner, the false image generated on the odd-numbered line and the false image generated on the even-numbered line cancel each other, and the image quality deterioration due to the false contour is reduced.

Each subfield period shown in FIG. 6 has at least an address period AP and a display period SP, and the time width of the display period, that is, the number of sustain pulses is weighted for each subfield period. Here, the display period of each subfield period is set to a binary code of 1: 2: 4: 8: 16: 3.
The ratio is 2: 64: 128. The start timing of each subfield period coincides between the odd line group and the even line group. That is, the address period of the odd-numbered line group and the address period of the even-numbered line group are synchronized. For example, the SF3 of the odd-numbered line and the SF4 of the even-numbered line are simultaneously driven, and a pixel to be lit is selected. In the display period, the start point is the same in the odd line group and the even line group, and the end point is different. That is, the display period is different between the subfield period of the odd line group and the subfield period of the even line group. This is shown in FIG.

FIG. 7 is a diagram showing a difference in display period between an odd line and an even line in the second conventional driving method.
As shown in FIG. 6, in the second conventional driving method,
The odd-numbered line subfield period SF1 and the even-numbered subfield period SF2 are simultaneously driven, and similarly, the odd-numbered line subfield period SF3 and the even-numbered line subfield period SF4 are simultaneously driven. As described above, one subfield period of the odd line group and one subfield period of the even line group are simultaneously driven.However, when the subfield period of the odd line and the subfield period of the even line driven simultaneously are compared. , The number is always shifted by one, which indicates that the display period of one subfield period is 倍 or twice the display period of the other subfield period.

In FIG. 7, for example, SFn is a subfield period SF3 of an odd line shown in FIG.
n + 1 is a subfield period S of an even line shown in FIG.
The description will be made assuming that F4. Comparing SFn and SFn + 1, the address period AP of both subfield periods has the same timing and the same time width, but the display period SP of SF3 is half of the display period of SF4.
Is 1/2 of the display period of SFn + 1. Therefore, in order to synchronize the odd-numbered lines and the even-numbered lines in driving the scan electrodes, a rest period having the same time width as the display period of SFn is provided after SFn. That is, the time width is the same as the SFn + 1 period by adding the pause period to the SFn period.

[0016]

In the second conventional driving method shown in FIG. 6, in order to synchronize the driving of the odd-numbered line group and the even-numbered line group, as shown in FIG. An idle period is provided after one subfield period, and this idle period is a period that is not used as an address period or a display period, and has contributed to a decrease in the brightness of the PDP and an increase in the unit display period. As the unit display period increases, the number of subfield periods that can be arranged in the unit display period decreases. For this reason, there is a problem that the number of gradations is easily restricted. SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and provides a method of driving a plasma display panel capable of reducing a pause period in a PDP display, increasing the brightness of the PDP, and shortening a unit display period. With the goal.

[0017]

SUMMARY OF THE INVENTION A method of driving a plasma display panel according to the present invention has been made to solve the above-mentioned problems, and a method of driving a plasma display panel according to the first invention has one subfield period. By having at least an address period and a weighted display period, the field period of the image signal is divided into N (N is an even number equal to or greater than 6) subfield periods corresponding to 2 N display gray scales. A method for driving a plasma display panel that displays an image with a gradation by dividing into an idle period and controlling the presence or absence of light emission in each subfield period, wherein one of an odd line and an even line is used. The arrangement of the subfield periods is as follows: the odd-numbered subfield periods are arranged in ascending order, counting from the smallest display period, and The even-numbered sub-field periods are arranged in descending order, and the arrangement of the sub-field periods in the other line includes the largest sub-field period of the display period and the odd-numbered sub-field periods starting from the smaller display period. And a subfield period other than the subfield period at the same position is arranged in the reverse order to the arrangement on the one line. In the present invention, the one field may be read as one frame, and the present invention may be applied to a frame image.

According to the driving method of the plasma display panel of the present invention, the field period of the image signal is divided into N (N is an even number of 6 or more) subfield periods corresponding to the number of display gradations (2 to the Nth power). The subfield period is divided into an idle period, and the arrangement of each subfield period is set near the center of the unit display period.
The subfield period having the longest light emission period corresponding to B is arranged. Further, in one or more subfield periods in which the display period and the subfield period corresponding to the MSB are small, the subfield periods having the same display period are simultaneously lit on the odd lines and the even lines. In the sub-field periods other than the sub-field period that is simultaneously driven and lit, the sub-field periods are arranged so that the odd line group and the even line group are in reverse order. As a result, the temporal fluctuation of the center of gravity of the light emission between adjacent pixels in the moving image is small, and the false image in the moving image is almost canceled between the odd lines and the even lines. Can be reduced. In addition, by shortening the pause period, it is possible to increase the display period and the number of display gradations.

A driving method for a plasma display panel according to a second aspect of the present invention is such that one subfield period has at least an address period and a weighted display period, and the field period of an image signal is set to 2N. Plasma that divides into N (N is an even number of 6 or more) subfield periods corresponding to the number of gradations and a pause period, and controls the presence or absence of light emission in each subfield period to display a gradation image. In the display panel driving method, the arrangement of the subfield periods in one of the odd line and the even line is performed by arranging the even subfield periods in ascending order, counting in ascending order of the display period, and thereafter arranging the odd number lines. The sub-field period is arranged in descending order, and the sub-field period on the other line is And the sub-field period is also large,
The odd number of subfield periods from the smaller display period are arranged at the same position as the arrangement in the one line, and the subfield periods other than the subfield period at the same position are arranged in the reverse order to the arrangement in the one line. This is a method for driving a plasma display panel to be arranged.

According to a third aspect of the present invention, there is provided a driving method of a plasma display panel, wherein one subfield period has at least an address period and a weighted display period, and the field period of an image signal is set to 2N. Plasma that divides into N (N is an odd number of 7 or more) subfield periods corresponding to the number of gradations and a pause period, and controls the presence or absence of light emission in each subfield period to display a gradation image. In the display panel driving method, the arrangement of the subfield periods in one of the odd line and the even line is performed by arranging the odd subfield periods in ascending order, counting in ascending order of the display period, and thereafter arranging the even numbered subfield periods. The sub-field period is arranged in descending order, and the sub-field period on the other line is And the sub-field period is also large,
The even-numbered subfield periods from the smaller display period are arranged at the same position as the arrangement in the one line, and the subfield periods other than the subfield period at the same position are arranged in the reverse order to the arrangement in the one line. This is a method for driving a plasma display panel to be arranged.

According to a fourth aspect of the present invention, there is provided a driving method of a plasma display panel, wherein one subfield period has at least an address period and a weighted display period, and a field period of an image signal is set to 2N. Plasma that divides into N (N is an odd number of 7 or more) subfield periods corresponding to the number of gradations and a pause period, and controls the presence or absence of light emission in each subfield period to display a gradation image. In the display panel driving method, the arrangement of the subfield periods in one of the odd line and the even line is performed by arranging the even subfield periods in ascending order, counting in ascending order of the display period, and thereafter arranging the odd number lines. The sub-field period is arranged in descending order, and the sub-field period on the other line is And the sub-field period is also large,
The even-numbered subfield periods from the smaller display period are arranged at the same position as the arrangement in the one line, and the subfield periods other than the subfield period at the same position are arranged in the reverse order to the arrangement in the one line. This is a method for driving a plasma display panel to be arranged.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In the present invention, the field period of an image signal is set to N (N = 3) corresponding to the number of display gradations (2 to the Nth power).
Is divided into a subfield period and an idle period, and the arrangement of the subfield period in one of the odd-numbered line and the even-numbered line is ascending in the odd-numbered subfield period counted in ascending order of the display period. And then arrange the even-numbered subfield periods in descending order, and the arrangement of the subfield periods in the other line is such that the subfield period having the largest display period and the subfield period having the small display period are arranged in the one line. A plasma display panel driving method is arranged at the same position as the arrangement on the line, and the subfield periods other than the subfield period at the same position are arranged in the reverse order to the arrangement on the one line.

The arrangement of the sub-field periods in one of the odd-numbered lines and the even-numbered lines is such that the even-numbered sub-field periods are arranged in ascending order, counting in ascending order of the display period, and thereafter the odd-numbered sub-field periods are arranged. May be arranged in descending order. When N is an even number equal to or greater than 6, two subfield periods having the same display period are simultaneously driven and lit by odd lines and even lines during the even number of subfield periods.
When N is an odd number of 7 or more, it is an odd number of subfield periods that two subfield periods having the same display period are simultaneously driven and lit by odd lines and even lines.

Hereinafter, first to fourth embodiments of the driving method of the plasma display panel according to the present invention will be described with reference to the drawings. The first to fourth embodiments described below correspond to the N
Is an even number of 6 or more, and two subfield periods having the same display period are simultaneously driven and lit by the odd line and the even line during the even number of subfield periods. Are circled for subfield periods having the same display period and being simultaneously lit on odd lines and even lines.

FIG. 1 is a diagram showing an arrangement of subfield periods in a method of driving a plasma display panel according to a first embodiment of the present invention. In the present invention, the plasma display panel to be driven is a general AC type plasma display panel as illustrated in FIG. 4, and the odd line group and the even line of both the X electrode and the Y electrode are driven by different driving circuits. In the first embodiment shown in FIG. 1, the image signal is 2 to the eighth power,
That is, in order to display at 256 gradations, the image signal is converted into an 8-bit image signal, and one field period is divided into eight subfield periods to display a halftone of the image.

In this example, each subfield period has at least an address period AP and a display period SP, and the time width of the display period SP, that is, the number of sustain pulses is weighted in each subfield period. That is, 1 which is the unit display period
The field period (1F) is divided into eight subfield periods and pause periods, and the arrangement of the subfield periods in the unit display period is SF1, SF3, SF in the odd line group.
5, SF7, SF8, SF6, SF4, SF2 in the order, and SF1, SF2, SF4, SF
6, SF8, SF7, SF5, and SF3.
Here, each subfield period SF1, SF2, SF
3, SF4, SF5, SF6, SF7, and SF8 are displayed in binary code 1: 2: 4: 8: 16: 32: 64:
128.

One subfield period of the odd line group and one subfield period of the even line group are driven in pairs. For example, SF1 of an odd line group and S1 of an even line group
F1, SF3 of the odd line group and SF2 of the even line group,
SF5 of the odd line group and SF4 of the even line group,...
And so on. The driving of these two combined subfield periods is started simultaneously. And those address periods have the same timing,
The starting points (timings) of these display periods are also the same.

Of the above combinations, the SF8 corresponding to the MSB is arranged at substantially the center of the unit display period 1F, is driven simultaneously by odd lines and even lines, and has the same address period and display period at exactly the same timing. The pause period shown in FIG. 7A is not set. L
The SF1 corresponding to the SB is arranged at the forefront of the unit display period, is driven simultaneously by the odd lines and the even lines, and has exactly the same timing in the address period and the display period, as shown in FIG. 7A. No pause period is set.

The subfield period corresponding to the MSB and L
In the arrangement of the subfield periods other than the subfield period corresponding to the SB, odd-numbered lines are counted in ascending order from the subfield period corresponding to the LSB, odd-numbered subfield periods are arranged first in ascending order, and then The third subfield period is arranged in descending order (in order of the light emission period). On the even-numbered line, after SF1, the even-numbered subfield periods are arranged first in ascending order, counting from the subfield period corresponding to the LSB, and then the odd-numbered subfield periods are arranged in descending order. This arrangement
In sub-field periods other than the sub-field period having the same display period, the odd-numbered lines and the even-numbered lines are arranged in reverse order.

FIG. 2 is a diagram for explaining a scanning electrode driving method according to the present invention.
FIG. 4 is a diagram showing a scanning pulse applied to an electrode. The scanning pulse is driven by separate driving circuits for the odd line group and the even line group, and is applied to each pixel in the address period AP in each subfield period according to the image signal. The Y electrodes corresponding to the odd-numbered line group are Y1, Y3, Y5,.
The Y electrodes corresponding to the even line groups are Y2, Y4, Y6,.

For example, in the address period of the subfield period SF1, as shown in FIG. 2, a scanning pulse is first applied to Y1 and Y2, then applied to Y3 and Y4, and sequentially an odd line Yn-1 and an even line. , And the address period AP of one subfield period ends. Although the timing of the scanning pulse in Y1 and the timing of the scanning pulse in Y2 are synchronized, the presence or absence of a pulse for each pixel is determined according to an image signal. Are different in nature and are provided by separate drive circuits.

On the other hand, the sustain pulse in the display period SP in the subfield period is equal to X in the plasma display panel.
The voltage is applied alternately to the electrode and the Y electrode. As for the sustain pulse applied to the X electrodes, the X electrodes of the odd-numbered line group are commonly connected to apply the same sustain pulse voltage waveform, and the X-electrodes of the even-numbered line group are also the same. Similarly, for the sustain pulse applied to the Y electrode, the odd line group and the even line group are driven by different drive circuits.

FIG. 9 is a diagram for comparing the time required for display between the first embodiment of the present invention and the second conventional example.
(A) is based on the first embodiment of the present invention, and (b) is based on the second conventional example. In the figure, the numbers written below each subfield period indicate that the display period of SF1 is 1, and the display period SP in the subfield period of the odd line and the even line is compared. The values are described. Note that, here, the time required for display indicates the address period excluded. As shown in FIG. 9B, when the display period of SF1 is 1, the odd line is SF1 and the even line is SF2, assuming that the display period of SF1 is 1. Is determined by SF2 and becomes 2. Each of SF2, SF4, SF6, and SF8 of even lines is 2,
8, 32 and 128, and SF8 and SF of odd lines
6, SF4, SF2, 128, 32, 8, 2 respectively
It is. Therefore, when these are totaled, the total period required for display within the unit display period 1F is 340.

Similarly, in the first embodiment of the present invention shown in FIG. 9A, the odd lines SF1, SF3, SF5, S
1, 4, 16, 64, 128 for F7 and SF8 respectively
And SF8, SF7, SF5, SF3 of even lines
Are 64, 16, and 4, respectively. Therefore, when these are totaled, the total period required for display within the unit display period 1F is 297. As described above, since the pause period shown in FIG. 7A does not occur in SF1 and SF8, the time required for display is shortened accordingly.

As described above, in the present invention, in order to simultaneously light the two subfield periods (SF1 and SF8) having the same display period in the odd line and the even line in several subfield periods, Compared with the arrangement of the subfield periods in which the false contour failure is said to be the least in the second conventional example, the order of the subfield periods in which the display period is short is changed. However, it is the subfield period having a longer display period that mainly contributes to the false contour failure. Even if the arrangement of the subfield period having a smaller display period is changed, a moving image is formed by odd lines and even lines. The effect of the pseudo contour suppression that the false images in each other cancel each other is hardly impaired.

Next, second to fourth embodiments of the method for driving the plasma display panel according to the present invention will be described. 2nd
The fourth embodiment is an example in which the N is an even number equal to or greater than 6, and FIG. 3 is a diagram showing the arrangement of subfield periods in the method of driving a plasma display panel according to the second to fourth embodiments of the present invention. . In FIG. 3, the value of N corresponding to the 2Nth number of gradations is 16, (a) shows the arrangement of the subfield periods in the odd-numbered line group in the second to fourth embodiments, and (b) () Shows the arrangement of the subfield periods in the even line group in the second embodiment. Similarly, (c) is the third
The arrangement of the subfield period in the even line group in the embodiment is shown, and (d) shows the arrangement of the subfield period in the even line group in the fourth embodiment.

The arrangement of the sub-field periods in the odd-numbered line group is such that the odd-numbered sub-field periods are arranged in ascending order, starting from the one with the shorter display period, and thereafter the even-numbered sub-field periods are arranged in descending order. In the arrangement of the subfield periods in the even line group, first, SF1 corresponding to the LSB and SF16 corresponding to the MSB are arranged at the same positions as SF1 and SF16 of the odd line, respectively.
In other subfield periods (other than the subfield period at the same position), the subfield periods are arranged in the order opposite to the arrangement in the odd-numbered lines. That is, the even-numbered subfield periods are arranged in ascending order, and thereafter the odd-numbered subfield periods are arranged in descending order. Thus, in the second embodiment, M
SF16 corresponding to SB and SF1 corresponding to LSB are:
The odd lines and the even lines are simultaneously driven and turned on.

In the third embodiment, the LSB having the shortest display period is used.
3 subfield periods (SF1, SF
2, SF3) and the SF16 corresponding to the MSB are simultaneously driven on odd-numbered lines and even-numbered lines. The arrangement of the other subfield periods is the same as in the second embodiment.

In the fourth embodiment, the LSB having the shortest display period is used.
5 subfield periods (SF1, SF
2, SF3, SF4, SF5) and S corresponding to the MSB
F16 is driven simultaneously on odd-numbered lines and even-numbered lines. The arrangement of the other subfield periods is the same as in the second embodiment. As in the fourth embodiment, when a plurality of sub-field periods (SF1, SF2, SF3, SF4, and SF5 in the example) with a short display period are simultaneously lit on odd lines and even lines, the target sub-field period is The selection is made in ascending order of the display period, and the number is set in consideration of the pseudo contour suppression effect.

Next, a description will be given of a fifth embodiment of the method for driving the plasma display panel according to the present invention. FIG. 10 is a diagram showing the arrangement of the subfield periods in the driving method of the plasma display panel according to the fifth embodiment of the present invention. The fifth embodiment is an example in which the value of N corresponding to the 2Nth number of gradations is an odd number. When N is an odd number, two subfield periods having the same display period are simultaneously lit on the odd line and the even line because the subfield period corresponding to the MSB and the subfield period corresponding to the LSB And the odd number of subfield periods. These simultaneous lighting subfield periods are marked with circles in the figure.

In the present embodiment, N is 9, and three sets of subfield periods (SF1, SF2, SF
9) is driven simultaneously by the odd line and the even line to light up. The arrangement of the sub-field periods in the odd-numbered lines is such that the odd-numbered sub-field periods are arranged in ascending order, starting from the one with the shorter display period, and thereafter the even-numbered sub-field periods are arranged in descending order. The arrangement of the subfield periods in the even line group includes SF1 having the shortest display period, SF2 having the next smallest display period, and S corresponding to the MSB.
F9 is arranged at the same position as SF1, SF2, SF9 of the odd line, and the subfield periods other than the subfield period of the simultaneous lighting are arranged in the reverse order of the arrangement in the odd line. That is, the even-numbered subfield periods are arranged in ascending order, and thereafter the odd-numbered subfield periods are arranged in descending order.

As described above, when N is an odd number, two subfield periods having the same display period are simultaneously lit on the odd line and the even line, in addition to the subfield period corresponding to the MSB. The even-numbered sub-field periods in the order of smaller display periods are the sub-field periods of simultaneous lighting. In the above-described first to fifth embodiments of the present invention, it goes without saying that the same effect can be obtained even if the arrangement of the sub-field periods is switched between odd lines and even lines. Furthermore, the arrangement of the subfield periods may be reversed, and the same effect can be obtained in such a case.

In each of the embodiments of the present invention described above, the subfield period corresponding to the MSB and the subfield period having a small display period are simultaneously driven by the odd-numbered lines and the even-numbered lines. In the sub-field period, since the arrangement order of the sub-field periods in the odd-numbered lines and the even-numbered lines is reversed, the false image and the pseudo outline in the moving image almost cancel each other between adjacent lines, and While maintaining the effect that image quality disorders are suppressed,
This has the effect of shortening the unit display period.

That is, in the subfield periods other than the simultaneous lighting subfield period, the display order is reversed between adjacent lines of the PDP, so that the front and rear edges in the moving direction of the moving image move. The brightness of the false image seen in FIG. 2 is inverted between the odd and even lines, the false image is canceled by the odd and even lines, and the image quality disturbance due to the false contour is suppressed. Since the pause period shown in FIG. 7A becomes unnecessary, the display period in each subfield period is extended to increase the luminance, or the value of N corresponding to the number of gradations is increased to increase the level. An effect of increasing the number of tones is achieved.

In the embodiment of the present invention, the plasma display panel has been described as an example. However, the present invention is not limited to this. One field is divided into a plurality of subfield periods, and the light emission time of each subfield period is controlled. The present invention can be similarly applied to a panel type display such as a liquid crystal which displays a halftone.

[Brief description of the drawings]

FIG. 1 is a diagram showing an arrangement of a subfield period in a method of driving a plasma display panel according to a first embodiment of the present invention.

FIG. 2 is a diagram illustrating a driving method of a scanning electrode according to the present invention.

FIG. 3 is a diagram showing an arrangement of subfield periods in a method of driving a plasma display panel according to the second to fourth embodiments of the present invention.

FIG. 4 is a diagram showing electrode wiring of an AC type plasma display panel.

FIG. 5 is a diagram showing a first conventional driving method of an AC type plasma display panel.

FIG. 6 is a diagram showing a second conventional driving method of an AC type plasma display panel.

FIG. 7 is a diagram showing a difference between display periods of odd lines and even lines in a second conventional driving method.

FIG. 8 is a diagram showing the correspondence between display gradations and display patterns.

FIG. 9 is a diagram for comparing the time required for display between the first embodiment of the present invention and the second conventional example.

FIG. 10 is a diagram showing an arrangement of a subfield period in a method of driving a plasma display panel according to a fifth embodiment of the present invention.

[Explanation of symbols]

 Y1, Y3, Y5-odd-numbered group of scanning electrodes Y2, Y4, Y6-odd-numbered group of scanning electrodes A1, A2, A3-address electrodes SF1, SF2, SF3-subfield period 400 panel 401 X electrode (light emission) Display sustain pulse applying electrode) 402 Y electrode (scanning pulse applying electrode) 403 A electrode (address pulse applying electrode) 404 Discharge cell

Continued on the front page F term (reference) 5C058 AA11 BA02 BA05 5C080 AA05 BB05 CC03 DD08 DD30 EE29 FF02 FF09 GG08 HH05 JJ02 JJ04 JJ05 KK02 KK43

Claims (4)

[Claims] 1. One sub-field period has at least an address period and a weighted display period.
The field period of the image signal is divided into N (N is an even number equal to or greater than 6) subfield periods and pause periods corresponding to 2 N display gray levels, and the presence or absence of light emission in each subfield period is determined. What is claimed is: 1. A method of driving a plasma display panel that displays an image having a gradation by controlling, wherein an arrangement of subfield periods in one of an odd line and an even line is odd-numbered counting in ascending order of the display period. Are arranged in ascending order, then the even-numbered subfield periods are arranged in descending order, and the arrangement of the subfield periods on the other line is determined by the subfield period having the largest display period and the subfield period having the smaller display period. And an odd number of subfield periods are arranged at the same position as the arrangement in the one line, and the subfields at the same position are arranged. The driving method of a plasma display panel, characterized in that arranged in reverse order of the subfield period other than the period between arrangement in the one line. 2. A method according to claim 1, wherein one subfield period has at least an address period and a weighted display period.
The field period of the image signal is divided into N (N is an even number equal to or greater than 6) subfield periods and pause periods corresponding to 2 N display gray levels, and the presence or absence of light emission in each subfield period is determined. What is claimed is: 1. A method of driving a plasma display panel that displays an image with gradation by controlling, wherein an arrangement of subfield periods in one of an odd line and an even line is an even number counting in ascending order of the display period. Are arranged in ascending order, then the odd-numbered subfield periods are arranged in descending order, and the arrangement of the subfield periods in the other line is determined by the subfield period having the largest display period and the smaller display period. And an odd number of subfield periods are arranged at the same position as the arrangement in the one line, and the subfields at the same position are arranged. The driving method of a plasma display panel, characterized in that arranged in reverse order of the subfield period other than the period between arrangement in the one line. 3. The method of claim 1, wherein one subfield period has at least an address period and a weighted display period.
The field period of the image signal is divided into N (N is an odd number of 7 or more) subfield periods and pause periods corresponding to 2 N display gray levels, and the presence or absence of light emission in each subfield period is determined. What is claimed is: 1. A method of driving a plasma display panel that displays an image having a gradation by controlling, wherein an arrangement of subfield periods in one of an odd line and an even line is odd-numbered counting in ascending order of the display period. Are arranged in ascending order, then the even-numbered subfield periods are arranged in descending order, and the arrangement of the subfield periods on the other line is determined by the subfield period having the largest display period and the subfield period having the smaller display period. And the even number of subfield periods are arranged at the same position as the arrangement in the one line, and the subfields at the same position are arranged. The driving method of a plasma display panel, characterized in that arranged in reverse order of the subfield period other than the period between arrangement in the one line. 4. One subfield period has at least an address period and a weighted display period.
The field period of the image signal is divided into N (N is an odd number of 7 or more) subfield periods and pause periods corresponding to 2 N display gray levels, and the presence or absence of light emission in each subfield period is determined. What is claimed is: 1. A method of driving a plasma display panel that displays an image with gradation by controlling, wherein an arrangement of subfield periods in one of an odd line and an even line is an even number counting in ascending order of the display period. Are arranged in ascending order, then the odd-numbered subfield periods are arranged in descending order, and the arrangement of the subfield periods in the other line is determined by the subfield period having the largest display period and the smaller display period. And the even number of subfield periods are arranged at the same position as the arrangement in the one line, and the subfields at the same position are arranged. The driving method of a plasma display panel, characterized in that arranged in reverse order of the subfield period other than the period between arrangement in the one line.